Accelerated Pacing and Cardiac Filling Pressures During Exercise in Patients With Heart Failure With Preserved Ejection Fraction

NCT ID: NCT07270536

Last Updated: 2026-01-08

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-12-10
• Study Completion Date: 2027-01-01

Brief Summary

Heart failure with preserved ejection fraction (HFpEF) is a condition where the heart pumps strongly enough, but has trouble relaxing and filling with blood properly. This causes the pressure on the left side of the heart to rise, especially during activity, which can lead to symptoms like shortness of breath and fatigue. Even light activities such as walking or climbing stairs can be difficult, limiting daily life.

Recent research suggests that increasing the heart rate in people with HFpEF may help lower this elevated pressure in the heart. Because patients usually experience their symptoms during exercise, this study aims to see whether, during light activity, increasing the heart rate in patients who already have a pacemaker by adjusting its settings, can reduce this elevated pressure in the heart. Furthermore, we will look at how increasing the heart rate affects the amount of blood the heart pumps each minute, another key factor in a person's ability to perform physical activity.

The investigators will examine 20 patients using a heart catheter to measure pressures, along with breathing analyses. During the measurements, all patients will perform light-intensity cycling.

If increasing the pacemaker rate lowers the pressure in the heart, this simple, non-drug-based intervention could improve daily functioning and comfort for thousands of patients with heart failure, justifying further long-term studies to evaluate effects beyond the immediate changes in heart pressures.

Detailed Description

The first phase of the study is the screening phase. During this phase, the investigators will review all patients from the LBBA pacing registries at UZ Leuven and Jessa Hospital to identify who may be eligible. From this review, the investigators will create a list of potential candidates, who will then be contacted during their regular check-up visits, which take place at least once a year. If a patient is found to be eligible during this visit, the study visit will be scheduled within three weeks.

If the patient remains eligible, the study tests will begin. A small tube (catheter) will be placed in a vein in the neck and in an artery in the wrist to measure heart pressures and blood oxygen levels. The patient will then be positioned on a slightly reclined stationary bike. During the test, the heart rate will be gradually increased in three steps by adapting the pacemaker settings, and at each step, the pressures inside the heart will be measured. In a final step, the heart rate will return to the level associated with the lowest heart pressure, and blood oxygen levels will be checked. This allows the research team to calculate how much oxygen the heart pumps per minute.

After the exercise, the patient will rest briefly while the catheters are safely removed.

The entire study visit lasts about three hours, after which participation ends. The full study is expected to be completed once 20 patients have finished all study tests, which should take approximately one year.

Conditions

HFpEF

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

All patients

Group Type: EXPERIMENTAL

Accelerated pacing with AV-delay optimization during rest and light intensity cycling

Intervention Type: OTHER

Patients will undergo one protocol at rest and two exercise protocols (10 Watts followed by 25 Watts). During each protocol, the pacemaker rate will be gradually increased in three stages. At each stage, intracardiac pressures and shear-wave velocity will be measured. In a final fourth stage, the pacemaker rate will return to the level associated with the lowest heart pressure, blood oxygen levels and oxygen uptake will be assessed.

Interventions

Accelerated pacing with AV-delay optimization during rest and light intensity cycling

Patients will undergo one protocol at rest and two exercise protocols (10 Watts followed by 25 Watts). During each protocol, the pacemaker rate will be gradually increased in three stages. At each stage, intracardiac pressures and shear-wave velocity will be measured. In a final fourth stage, the pacemaker rate will return to the level associated with the lowest heart pressure, blood oxygen levels and oxygen uptake will be assessed.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Voluntary written informed consent of the participant has been obtained prior to any screening procedures

2. At least 18 years of age at the time of signing the Informed Consent Form (ICF)

3. Heart failure with preserved ejection fraction, defined as one of the below criteria:

1. HFA-PEFF score >= 5 or

2. H2FPEF score >= 6 or

3. EF >= 50% and

i. Heart failure hospitalization after pacemaker implantation or ii. On loop-diuretics at time of inclusion

4. Having a DDD-pacemaker with LBB area pacing, implanted at least 12 weeks before iCPET

5. >=6 weeks on optimal HFpEF therapy (MRA and SGLT2i), unless contraindicated or not tolerated

6. Sinus rhythm at time of screening and iCPET

Participants eligible for this Study must not meet any of the following criteria:

1. Participant has a history of:

1. Evidence of significant pulmonary comorbidity based on abnormal pulmonary function tests (FEV1 <60%) or aberrant lung parenchyma more than mild on radiological imaging

2. Severe/symptomatic valvular diseases

3. Severe pulmonary hypertension (PASP > 55mmHg estimated by Doppler Echo)

4. Unstable arrhythmias (VT, VF)

5. Recurrent syncopes after pacemaker implantation

6. Episode of atrial fibrillation in the last 3 months

7. Amyloid cardiomyopathy

2. Physical inability to perform exercise

3. More than 1 hospitalization for heart failure in the last year

4. Resting heart rate> 100bpm

5. At time of iCPET or inclusion: decompensated heart failure, unstable coronary syndrome

6. Contraindication to central venous access

1. Severe coagulopathy (e.g., spontaneous INR > 2, thrombocytopenia < 50,000/µL)

2. Local infection or skin infection at the insertion site

3. Thrombosis or anatomical abnormalities of the right jugular vein

4. Pneumothorax or contralateral lung pathology

5. Inability to properly position the patient

7. Contraindication to arterial access

1. Thrombosis or occlusion of the target artery

2. Raynaud's phenomenon or other vasospastic disorders

3. Active infection at the intended insertion site

4. Severe coagulopathy (e.g., spontaneous INR > 2, thrombocytopenia < 50,000/µL)

5. Insufficient collateral circulation (e.g., inadequate perfusion in an Allen test)

8. Contraindications to CPET

1. ECG signifying myocardial injury

2. ECG signifying current or potentially lethal arrhythmias

3. Systemic hypotension (e.g. systolic blood pressure < 90 mmHg)

4. Extreme hypertension (e.g. systolic blood pressure > 220 mmHg)

5. Syncope, presyncope, or lightheadedness

6. SaO2 < 88%

7. Severely elevated PCWP (> 40 mmHg) during exercise

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Jessa Ziekenhuis Hasselt

UNKNOWN

Sponsor Role: collaborator

Universitaire Ziekenhuizen KU Leuven

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Jessa Ziekenhuis Hasselt

Hasselt, , Belgium

Site Status: RECRUITING

University Hospitals Leuven

Leuven, , Belgium

Site Status: RECRUITING

Countries

Belgium

Central Contacts

Margot Vermeiren, MD

Role: CONTACT

margot.vermeiren@kuleuven.be

+3216332211

Facility Contacts

Jan Verwerft, MD PhD

Role: primary

jan.verwerft@jessazh.be

Margot Vermeiren, MD

Role: primary

margot.vermeiren@kuleuven.be

+3216332211

Role: backup

margotvermeiren97@gmail.com

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

S70922

Identifier Type: -

Identifier Source: org_study_id